These Kodachrome photos of 1940s London are beautiful, but the real excitement comes from this comment:
When we launch The Retroscope around July, it will be possible to stand at the same vantage points and, using a smartphone, see these pictures hovering over the scene as it is now, in Augmented Reality[.]
¶ In a similar vein, the Museum of the Phantom City iPhone app allows people to find and then view imagined landscapes.